This invention relates to fluid ball and socket couplings for connecting high pressure fluid hoses or for connecting a fluid supply high pressure hose to a spray nozzle.
U.S. Pat. No. 1,087,006 discloses a spray nozzle coupled to a hose with a ball and socket coupling comprising a metal ball connected in a metal socket that is spun about the ball to retain the socket on the ball. This arrangement is subject to leakage.
U.S. Pat. No. 2,557,106 discloses a similar device which suffers from a similar deficiency.
U.S. Pat. No. 2,971,701 discloses a ball and socket arrangement employing an O-ring in combination with a split ring. A coupling nut engages the ball. The split ring permits universal pivoting of the ball. In a further embodiment resilient fingers engage the ball to bias the ball toward the split ring. In other embodiments a spring biases the ball.
In U.S. Pat. No. 3,022,014 a ball and socket arrangement is shown for a shower head. The ball is seated at one region against a packing and at another region is retained by a nut that has a shoulder that engages the ball.
U.S. Pat. No. 3,224,793 shows a ball and socket arrangement wherein an O-ring is used in combination with a split ring, the ring for retaining the ball in the socket.
In U.S. Pat. No. 3,334,818 to Moen, a swivel and socket arrangement is shown in which an adapter is threaded to a mounting member forming a socket. An O-ring seals against the swivel and against the adapter and mounting member. The adapter squeezes against the O-ring. An undescribed member also abuts the ball distal the adapter apparently for retaining the swivel in the socket in one axial direction. It appears that the O-ring holds the swivel axially in place so the swivel will not displace toward the adapter away from the retaining member in the opposite axial direction. This function, however, is not expressly described per se. The end of the swivel, which is ball shaped, adjacent to the adapter, is spaced from the adapter. It thus appears that the O-ring is both a seal and a retainer member.
In U.S. Pat. No. 3,921,912 a spherical member and gudgeon arrangement for a lawn sprinkler is disclosed. An O-ring abuts the member in the socket of the gudgeon and the spherical member also abuts the socket of the gudgeon directly.
Metal to metal contact in certain of the above patent devices is undesirable as it causes galling. Galling creates metal chips which can harm the O-rings which are typically rubber and thus cause leakage. In others of the above patents, the O-ring serves as both a sealing member and a retaining member. Since O-rings are typically made of rubber or other elastomeric material, high pressure between the O-ring and the mating members creates relatively high friction. This friction interferes with the operation of such devices. In some cases, it is known that silicon grease may be used on the O-rings to reduce friction. However, eventually such grease dissipates, especially in the presence of hot fluids, and the high friction returns.
The present invention is directed to provide a solution to the above problems.
A fluid coupling device according to one aspect of the present invention comprises a male member with an outer spherical surface and a fluid receiving bore passing through the member in communication with opposing first and second ends. A housing has a circular cylindrical chamber defining a longitudinal axis and is of a first transverse dimension, the chamber being open at third and fourth opposite housing ends, the fourth end having a reduced transverse dimension opening, at least a portion of the male member spherical surface being received in the chamber, the reduced dimension fourth end for retaining the male member in the chamber in a first direction along the axis. A nipple member includes a nipple at a first nipple member end and a coupling member at a second nipple member end, the nipple for receiving and coupling a fluid source to the male member fluid receiving bore in the chamber, the coupling member and housing being arranged for axially attaching the nipple member to the housing at the circular cylindrical chamber for retaining the male member in the chamber in a second direction opposite the first direction.
First and second annular seat members have an outer peripheral surface and a radially inward surface, the seat members being located in the cylindrical chamber in spaced axial aligned relation along the axis and abutting the housing in the chamber on their outer peripheral surface, the seat members abutting the spherical surface on their radially inward surfaces and dimensioned for receiving equal and opposite axial forces from and to the spherical surface, the seat members exhibiting negligible friction on their surfaces abutting the spherical surface.
A seal is in the chamber for fluid sealing the chamber between the housing and male member and between the housing and nipple member and for transferring an axial locking load to the first and second seat members, and to the male member from the nipple member.
In one aspect, the seat members comprise polytetrafluoroethylene at their radially inward surfaces.
Preferably the seal is an O-ring.
In a further aspect, the radially inward surfaces of the seat members each have inner inclined planar surfaces relative to the longitudinal axis.
In a further aspect, the seat members are identical.
In a further aspect, the coupling member includes an externally threaded member for engaging mating housing internal threads in the chamber, the threaded member having an end surface sealingly engaging the seal.
In a further aspect, the housing has an annular recessed shoulder at the chamber including a further seal sealingly engaging the recessed shoulder and the coupling member.
In a still further aspect, a fluid coupling device comprises a male member with an outer spherical surface of a given diameter and a fluid receiving bore passing through the member, the male member having opposing first and second ends. A housing has a circular cylindrical chamber of a first transverse dimension defining a longitudinal axis, the chamber being open at third and fourth housing ends on the axis, the fourth end having a reduced transverse dimension opening, at least a portion of the male member spherical surface being received in the chamber, the reduced dimension fourth end being smaller than the spherical surface diameter.
A nipple member includes a nipple and a coupling member at opposite ends, the nipple for receiving and coupling a fluid source to the male member fluid receiving bore, the coupling member and housing being arranged to secure the nipple member to the housing to retain the male member in the chamber at the third end. First and second annular seat members have an outer peripheral surface and a radially inward surface, the seat members being located in the cylindrical chamber in spaced axial aligned relation along the axis and abutting the housing in the chamber on their outer peripheral surface, the seat members abutting the spherical surface on their radially inward surfaces and dimensioned for receiving equal and opposite axial forces from and to the spherical surface, the seat members exhibiting negligible friction on their surfaces abutting the spherical surface.
An O-ring is in the chamber between the housing and male member and between the housing and nipple member for transferring an axial locking load to the first and second seat members, and to the male member from the nipple member.
In a further aspect, the seat members engage the spherical surface in an annular line contact.
In a further aspect, the regions of the seat member surfaces and the engaged spherical surface define different configurations.